[GFS2] The core of GFS2

This patch contains all the core files for GFS2.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 199 insertions, 0 deletions

diff --git a/fs/gfs2/ops_vm.c b/fs/gfs2/ops_vm.c
new file mode 100644
index 00000000000000..a1b409ce75e1cb
--- /dev/null
+++ b/fs/gfs2/ops_vm.c
@@ -0,0 +1,199 @@
+/*
+ * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
+ * Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU General Public License v.2.
+ */
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/buffer_head.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <asm/semaphore.h>
+
+#include "gfs2.h"
+#include "bmap.h"
+#include "glock.h"
+#include "inode.h"
+#include "ops_vm.h"
+#include "page.h"
+#include "quota.h"
+#include "rgrp.h"
+#include "trans.h"
+
+static void pfault_be_greedy(struct gfs2_inode *ip)
+{
+	unsigned int time;
+
+	spin_lock(&ip->i_spin);
+	time = ip->i_greedy;
+	ip->i_last_pfault = jiffies;
+	spin_unlock(&ip->i_spin);
+
+	gfs2_inode_hold(ip);
+	if (gfs2_glock_be_greedy(ip->i_gl, time))
+		gfs2_inode_put(ip);
+}
+
+static struct page *gfs2_private_nopage(struct vm_area_struct *area,
+					unsigned long address, int *type)
+{
+	struct gfs2_inode *ip = get_v2ip(area->vm_file->f_mapping->host);
+	struct gfs2_holder i_gh;
+	struct page *result;
+	int error;
+
+	atomic_inc(&ip->i_sbd->sd_ops_vm);
+
+	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &i_gh);
+	if (error)
+		return NULL;
+
+	set_bit(GIF_PAGED, &ip->i_flags);
+
+	result = filemap_nopage(area, address, type);
+
+	if (result && result != NOPAGE_OOM)
+		pfault_be_greedy(ip);
+
+	gfs2_glock_dq_uninit(&i_gh);
+
+	return result;
+}
+
+static int alloc_page_backing(struct gfs2_inode *ip, struct page *page)
+{
+	struct gfs2_sbd *sdp = ip->i_sbd;
+	unsigned long index = page->index;
+	uint64_t lblock = index << (PAGE_CACHE_SHIFT - sdp->sd_sb.sb_bsize_shift);
+	unsigned int blocks = PAGE_CACHE_SIZE >> sdp->sd_sb.sb_bsize_shift;
+	struct gfs2_alloc *al;
+	unsigned int data_blocks, ind_blocks;
+	unsigned int x;
+	int error;
+
+	al = gfs2_alloc_get(ip);
+
+	error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
+	if (error)
+		goto out;
+
+	error = gfs2_quota_check(ip, ip->i_di.di_uid, ip->i_di.di_gid);
+	if (error)
+		goto out_gunlock_q;
+
+	gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE,
+			      &data_blocks, &ind_blocks);
+
+	al->al_requested = data_blocks + ind_blocks;
+
+	error = gfs2_inplace_reserve(ip);
+	if (error)
+		goto out_gunlock_q;
+
+	error = gfs2_trans_begin(sdp,
+				 al->al_rgd->rd_ri.ri_length +
+				 ind_blocks + RES_DINODE +
+				 RES_STATFS + RES_QUOTA, 0);
+	if (error)
+		goto out_ipres;
+
+	if (gfs2_is_stuffed(ip)) {
+		error = gfs2_unstuff_dinode(ip, gfs2_unstuffer_page, NULL);
+		if (error)
+			goto out_trans;
+	}
+
+	for (x = 0; x < blocks; ) {
+		uint64_t dblock;
+		unsigned int extlen;
+		int new = 1;
+
+		error = gfs2_block_map(ip, lblock, &new, &dblock, &extlen);
+		if (error)
+			goto out_trans;
+
+		lblock += extlen;
+		x += extlen;
+	}
+
+	gfs2_assert_warn(sdp, al->al_alloced);
+
+ out_trans:
+	gfs2_trans_end(sdp);
+
+ out_ipres:
+	gfs2_inplace_release(ip);
+
+ out_gunlock_q:
+	gfs2_quota_unlock(ip);
+
+ out:
+	gfs2_alloc_put(ip);
+
+	return error;
+}
+
+static struct page *gfs2_sharewrite_nopage(struct vm_area_struct *area,
+					   unsigned long address, int *type)
+{
+	struct gfs2_inode *ip = get_v2ip(area->vm_file->f_mapping->host);
+	struct gfs2_holder i_gh;
+	struct page *result = NULL;
+	unsigned long index = ((address - area->vm_start) >> PAGE_CACHE_SHIFT) + area->vm_pgoff;
+	int alloc_required;
+	int error;
+
+	atomic_inc(&ip->i_sbd->sd_ops_vm);
+
+	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
+	if (error)
+		return NULL;
+
+	if (gfs2_is_jdata(ip))
+		goto out;
+
+	set_bit(GIF_PAGED, &ip->i_flags);
+	set_bit(GIF_SW_PAGED, &ip->i_flags);
+
+	error = gfs2_write_alloc_required(ip,
+					  (uint64_t)index << PAGE_CACHE_SHIFT,
+					  PAGE_CACHE_SIZE, &alloc_required);
+	if (error)
+		goto out;
+
+	result = filemap_nopage(area, address, type);
+	if (!result || result == NOPAGE_OOM)
+		goto out;
+
+	if (alloc_required) {
+		error = alloc_page_backing(ip, result);
+		if (error) {
+			page_cache_release(result);
+			result = NULL;
+			goto out;
+		}
+		set_page_dirty(result);
+	}
+
+	pfault_be_greedy(ip);
+
+ out:
+	gfs2_glock_dq_uninit(&i_gh);
+
+	return result;
+}
+
+struct vm_operations_struct gfs2_vm_ops_private = {
+	.nopage = gfs2_private_nopage,
+};
+
+struct vm_operations_struct gfs2_vm_ops_sharewrite = {
+	.nopage = gfs2_sharewrite_nopage,
+};
+